The defender has returned to the club where he made 12 appearances on loan last season for an undisclosed fee.
Stanley boss Paul Cook revealed the 22-year-old's arrival would compensate for the loss of Kevin McIntyre to Rochdale.
"We can't speak highly enough of the lad," he told the club's official website. "We brought him in to play left-back for us last year but because of injury and suspension he was forced to play centre-half and in midfield.
"We're convinced that he can come in and step into Kevin McIntyre's shoes at left-back and I'm sure he'll go on to have a great career with the club."
Liddle, who had a year remaining on his deal with the Black Cats, added: "When I realised that I wasn't going to get a chance at Sunderland my first thought was to try to get back to Accrington. I enjoyed it so much that I wanted to get back here as soon as I could."